/Engine/Plugins/Editor/ModelingToolsEditorMode/Source/ModelingToolsEditorMode/Public/ModelingToolsEditorModeToolkit.h
Override this function to extend the secondary mode toolbar (that appears below the main toolbar) for your mode by filling in theUToolMenuthat is passed in
virtual void ExtendSecondaryModeToolbar ( [UToolMenu](API\Developer\ToolMenus\UToolMenu) * InModeToolbarMenu )